diff --git a/firmware/common/disk.c b/firmware/common/disk.c
index 400d21f359..a23d51dbb8 100644
--- a/firmware/common/disk.c
+++ b/firmware/common/disk.c
@@ -223,6 +223,9 @@ int disk_mount(int drive)
         DEBUGF("No partition found, trying to mount sector 0.\n");
         if (!fat_mount(IF_MV2(volume,) IF_MD2(drive,) 0))
         {
+#ifdef MAX_LOG_SECTOR_SIZE
+            disk_sector_multiplier = fat_get_bytes_per_sector(IF_MV(volume))/SECTOR_SIZE;
+#endif
             mounted = 1;
             vol_drive[volume] = drive; /* remember the drive for this volume */
         }
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index a99341d58f..f055f4b170 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -448,6 +448,19 @@ static int fat_mount_internal(IF_MV2(int volume,) IF_MD2(int drive,) long starts
     return 0;
 }
 
+#ifdef MAX_LOG_SECTOR_SIZE
+int fat_get_bytes_per_sector(IF_MV_NONVOID(int volume))
+{
+#ifdef HAVE_MULTIVOLUME
+    if(!fat_bpbs[volume].mounted)
+        return 0;
+    return fat_bpbs[volume].bpb_bytspersec;
+#else
+    return fat_bpbs[0].bpb_bytspersec;
+#endif
+}
+#endif
+
 int fat_mount(IF_MV2(int volume,) IF_MD2(int drive,) long startsector)
 {
 #ifndef HAVE_MULTIVOLUME
diff --git a/firmware/export/fat.h b/firmware/export/fat.h
index 5df5dc4b91..36beda711d 100644
--- a/firmware/export/fat.h
+++ b/firmware/export/fat.h
@@ -99,6 +99,7 @@ extern void fat_unlock(void);
 #endif
 
 extern void fat_init(void);
+extern int fat_get_bytes_per_sector(IF_MV_NONVOID(int volume));
 extern int fat_mount(IF_MV2(int volume,) IF_MD2(int drive,) long startsector);
 extern int fat_unmount(int volume, bool flush);
 extern void fat_size(IF_MV2(int volume,) /* public for info */